If you need a lightweight and compact monitor for your DSLR and nicely to improve ability to get accurate focus, rather than using the DSLR screen.  MustHD 5 inch M501H field monitor is just fit for your need. It has many features like focus assist peaking, histogram etc and build quality. Great monitor if you are on a budget.
MustHD M501H

Focus Assist

M501H - Focus Peaking

Histogram
M701S - Histogram

Package

M501H Box

In the Box